1. Field of the Invention
The present invention relates to a water heater with a flame arrester set in a garage, a cellar, a warehouse and the like where inflammable materials such as gasoline, thinner, benzine and the like generating combustible vapor are stored.
2. Description of the Related Art
Conventionally, in this kind of a water heater with a flame arrester, for example, as shown in FIG. 19, a hot water storage chamber 2 and a combustion chamber 3 are provided upward and downward within a hollow cylindrical body 1, the combustion chamber 3 is provided with an exhaust passage 5 which penetrates the shaft center position and has an air supply inlet 4 and an opening on the upper portion of the body 1 for exhausting combustion gas within the combustion chamber 3, and further, a flame arrester (flame interruption apparatus) 6 is provided on the air supply inlet 4. A water heater with a flame arrester is made so that when exhaust gas at a high temperature burned with a gas burner 3a provided within the combustion chamber 3 passes through the exhaust passage 5, water supplied within the hot water storage chamber 2 is heated by the exhaust gas and stored as hot water at the predetermined temperature and then supplied to the outside of the water heater as appropriate. The flame arrester 6 is made of metal in a plate shape which is provided with a large number of minute openings such as a punching metal or an expand metal. Each inflammable gas has a quenching distance which is the largest gap that flame can not go through without being extinguished, since the flame arrester 6 utilizes this principle, the opening is made in a minute shape and the size of it is made in the range on the order of φ1.5-3 mm.